\chapter{Numbers and statistics}
\label{app:num_stat}

This list is taken from~\cite{SciWriting}.

\begin{itemize}
    \item Use symbol $\sim$ to mean approximately equal to.
    \item Numbers beginning a sentence must be spelled. It is usually better to rewrite a sentence so you don't start it with numbers greater than ninety-nine. Note: one, two, three\dots nine, 10, 11, 12\dots Exceptions: a 2-m tape measure; 3 million.
    \item Put a space between numbers and units: for example, $75$ kg. Exception: $75\%$. Note: $0.32$ is correct, NOT $.32$.
    \item When you quote numbers, make sure you use the minimum number of significant digits or decimal places. For example, $23 \pm 7$ years is appropriate but not $23.4 \pm 6.6$ years; the loss of accuracy is not important because the measurement is not significant to the first decimal place.  However $23.4 \pm 0.6$ is correct because this measurement is accurate to the first decimal place
    \item Use the appropriate number of digits: two significant digits for standard deviations (one digit if the standard deviation is for a descriptive statistic like height or weight, or if precision is not important); two decimal places for correlations, two significant digits for percentages. Examples: $73 \pm 5$; $r = 0.45$; $r = 0.08$; $16\%$; $1.3\%$; $0.013\%$.
    \item Make sure the significant digits of the mean and standard deviation are consistent. Examples:
$20 \pm 13$; $0.020 \pm 0.013$; $156 \pm 7$; $1.56 \pm 0.07$; $15600 \pm 700$ NOT $1.6 \pm 0.07$ or $20 \pm 13.1$
\end{itemize}
